An experimentally validated computational model for progressive damage analysis of notched oxide/oxide woven ceramic matrix composites

摘要

The focus of this paper is to examine the effect of a notch on the failure response of an oxide/oxide ceramic matrix composite (CMC) subjected to room-temperature tensile loading. The CMC is made of aluminosilicate matrix reinforced by 3M Nextel(TM) 610 alumina fibers (AS/N610) that are woven into an eight-harness satin weave (8HSW) preform. Uniaxial tensile tests were carried out on both un-notched and single-edge-notched tensile (SENT) specimens of two different lay-ups, (0/90)(S) and (45/0/ - 45/0)(S), using a hydraulically activated load frame. The digital image correlation (DIC) technique was utilized to map the deformation histories and identify the locations of strain concentration for both unnotched and SENT specimens. The experimental results were subsequently used to develop a lamina-level constitutive model for a single 8HSW ply that incorporates damage and fracture mechanics implemented through a finite element (FE) framework. A secant-modulus approach was employed to model the pre-peak nonlinear damage evolution, while the post-peak softening was modeled using the smeared crack approach (SCA). Utilizing the ply properties measured from the un-notched (0/90)(S) and (45/0/ - 45/0)(S) tension tests, the proposed computational model is able to predict the failure strength and strain localization in the SENT specimens. Such a predictive model can aid in the design of CMC structures and accelerate the development of CMCs for engineering applications. (C) 2016 Elsevier Ltd. All rights reserved.